As the demand for oil and other natural resources has resulted in mining and drilling operations in increasingly remote locations, the ability to gain access to these areas has become increasingly important. For instance, some remote areas are accessible in the winter by use of ice roads. As summer approaches, however, the thawing ice can make transport to these remote locations dangerous and/or destructive of the environments, e.g. the permafrost. A method of safely transporting heavy loads over these areas is a challenge of great importance.
Loads of large equipment or supplies can be exceedingly heavy. The power required to lift such loads with conventional machinery, such as helicopters, increases twofold as the weight of the machinery increases with the weight of the load. As greater load carrying capabilities are required, a solution is needed that will be able to lift very heavy loads without significantly increasing the weight of the lifting machinery. This will reduce the amount of power required and reduce the cost of transporting heavy loads to remote locations. Consider, for example, a helicopter with the capability to lift a load of 25,000 lbs. These same engines and rotors would be capable of lifting much more if the weight of the helicopter itself could be eliminated.
Solutions to this problem include utilizing a lighter-than-air transport to assist in carrying the required loads. One prior art example discloses a dirigible-type airship providing a lighter-than-air envelope that is tethered to one power source that controls the vectoring of the system and another power source that controls the lifting capability. See U.S. Pat. No. 4,695,012. The height of the system, measured from the balloon to the actual load, is very large, making the manufacturing and assembly difficult and expensive. The operation of the system is also difficult as the multiple power systems must be controlled independently. Another example of the prior art provides a large balloon with vectoring engines on the side of the balloon and lift rotors on a truss structure underneath the balloon.
Since these and other similar prior art designs require multiple power systems for vertical lift and vectoring thrust, operational controls are complex. Moreover, the support systems and structure are large and difficult to assemble. The overall weight of the structure is large and necessitates an increase in the size of the lighter-than-air element. This overall size increase and complexity of design also results in a housing problem as special hangars or support buildings are required. Maintenance is also an issue with these designs as many of the systems are difficult to access.